1. Field of the Invention
The present invention relates to a semiconductor device.
2. Description of the Prior Art
A light receiving sensor (or a semiconductor device) for receiving light, which is represented by a CMOS sensor in recent years, is built in an electronic device capable of picking up an image, such as a digital still camera, a digital video camera or the like. It is generally known that the light receiving sensor includes a plate-like semiconductor element (or an imaging element) for receiving light, a glass substrate arranged on a light-incident side of the semiconductor element in a spaced-apart facing relationship with the semiconductor element and a wall portion (or an adhesive portion) for bonding the semiconductor element and the glass substrate together, the wall portion made of a resin material. In the light receiving sensor, an internal space surrounded by the semiconductor element, the glass substrate and the wall portion is hermetically sealed.
Prior to shipment, the light receiving sensor configured as above goes through evaluation tests that evaluate whether the light receiving sensor is acceptable (reliable). Among the evaluation tests, there is a durability test by which the durability of the light receiving sensor is tested in an atmosphere of high temperature and high humidity (e.g., at the temperature of 85° C. and the humidity of 85%). The durability test is carried out by means of, e.g., a handler (or a semiconductor test device or a semiconductor conveyance device). The handler has a chamber in which the atmosphere of high temperature and high humidity as noted above can be set. The durability test is performed by installing the light receiving sensor within the chamber kept in the above atmosphere. During the course of performing the durability test, a vapor (or an air containing moisture) flows into an internal space of the light receiving sensor through the wall portion. When the light receiving sensor is taken out from the chamber at the end of the durability test, the internal space is filled with the vapor (which is not sufficiently discharged through the wall portion). For that reason, it is sometimes the case that the vapor comes into a saturated state. In this case, dew condensation occurs on an inner surface of the wall portion or the glass substrate.
As a solution to the dew condensation problem mentioned above, there has been proposed a light receiving sensor having a flow path formed in a wall portion so that an internal space can communicate with the outside therethrough and a vapor can pass therethrough (see, e.g., JP Patent No. 3830495). In this light receiving sensor, the vapor in the internal space is allowed to flow to the outside through the flow path. However, dust may be infiltrated into the internal space from the outside through the flow path. Once the dust is infiltrated into the internal space, it is impossible to remove the dust.